Insulation resistance measurement device and insulation resistance measurement method

Abstract

An insulation resistance measurement device includes a jig unit, a control unit and a transfer mechanism. The jig unit includes a lower jig having a reference surface, an upper jig having an abutting surface, a probe unit and a servomotor. When the upper jig is lowered toward the lower jig by the servomotor, the probe contacts a portion to be measured. When the upper jig is lowered further and the abutting surface of the upper jig abuts the reference surface, a torque of the servomotor increases. When the torque reaches a predetermined value, an insulation resistance is measured by the probe in a state where the torque is maintained.

What is claimed is: 
     
       1. An insulation resistance measurement device which measures an insulation resistance of a portion to be measured of a workpiece comprising:
 a lower jig having a reference surface and a workpiece placement surface; 
 an upper jig having an abutting surface opposed to the reference surface; 
 a probe unit including a first probe and a second probe disposed in the upper jig and projecting toward the workpiece placement surface, and a first spring and a second spring which urge the probes downward; 
 a lifting/lowering mechanism which includes a servomotor which lowers the upper jig toward the lower jig, and causes the probes to contact the portion to be measured and causes the abutting surface to abut the reference surface; and 
 a control unit which measures, when a torque of the servomotor increases and reaches a predetermined value in a state where the probes contact the portion to be measured and the abutting surface abuts the reference surface, the insulation resistance of the portion to be measured by the probes in a state where the torque is maintained. 
 
     
     
       2. The insulation resistance measurement device of  claim 1 , wherein the workpiece comprises a suspension,
 wherein the insulation resistance measurement device further comprises a transfer mechanism which transfers a suspension chain blank in which a plurality of suspensions are arranged with a predetermined pitch, 
 wherein the transfer mechanism includes an actuator which places a tail pad portion of one of the suspension suspensions on the workpiece placement surface. 
 
     
     
       3. The insulation resistance measurement device of  claim 1 , wherein the probe unit includes:
 the first probe, which contacts a first contact portion of the portion to be measured; 
 the first spring, which urges the first probe downward; 
 the second probe, which contacts a second contact portion of the portion to be measured; and 
 the second spring, which urges the second probe downward, and 
 wherein a distal end of the first probe abuts the first contact portion, a distal end of the second probe abuts the second contact portion, and the abutting surface abuts the reference surface in a state where the first spring and the second spring are compressed, respectively. 
 
     
     
       4. The insulation resistance measurement device of  claim 1 , wherein
 the lower jig has the workpiece placement surface located at a lower position than the reference surface, and 
 the upper jig has a probe mounting surface located at a higher position than the abutting surface. 
 
     
     
       5. The insulation resistance measurement device of  claim 1 , wherein
 the reference surface and the abutting surface are each formed of a flat surface extending in a horizontal direction, and 
 the reference surface and the abutting surface are parallel to each other. 
 
     
     
       6. An insulation resistance measurement method of measuring an insulation resistance of a portion to be measured of a workpiece comprising:
 placing the portion to be measured of the workpiece on a workpiece placement surface of a lower jig disposed on a measurement stage; 
 lowering an upper jig including probes toward the portion to be measured by a servomotor; 
 causing distal ends of the probes to abut the portion to be measured; 
 urging the probes toward the portion to be measured by springs; 
 lowering the upper jig further by the servomotor in a state where the distal ends of the probes abut the portion to be measured; 
 causing an abutting surface of the upper jig to abut a reference surface of the lower jig; 
 increasing a torque of the servomotor in a state where the abutting surface abuts the reference surface; and 
 measuring, when the torque reaches a predetermined value, the insulation resistance of the portion to be measured by the probes in a state where the torque is maintained. 
 
     
     
       7. The insulation resistance measurement method of  claim 6 , wherein a lower die of a die set used for processing the workpiece is used as the lower jig, and an upper die of the die set is used as the upper jig.